Zen-- It's a hard call as what you saw could be just about anything-- and not just fish. Anything that's separated from the bottom will show as long as it's big enough or solid enough.

Things, besides fish, that it could be include turbulence of some kind-- bubbles or even a rip line will show as fish. Trash, beer cans, sticks will all show as well. OR it could be fish.

I've seen bunches of "fish" on my side finder, and I've yet to catch anything using it. Of course, that could be a result of my fishing skills...

So why didn't you catch one so we would know the answer?

Keith